Influence of PSK (Krestin) on resistance to infection ofPseudomonas aeruginosa in tumor-bearing mice

Summary C3H/He mice were inoculated withPseudomonas aeruginosa by various routes 1 day after X5563 transplantation or 4 days after cyclophosphamide (CY) administration. Administration of PSK (Krestin) i.p. or p.o. to the tumor-bearing mice or CY-treated tumor-bearing mice resulted in an increase in survival rates. ViableP. aeruginosa were inoculated i.v. on day 0 into mice inoculated with tumor cells on day -12 and vaccinated with killedP. aerouginosa on day -10, or into mice inoculated with tumor cell on day -15, treated with CY on day -14 and vaccinated on day -10. Resistance to infection, which is enhanced by vaccination, was depressed by tumor burden or treatment with CY, but such depression was prevented by PSK administration.Abbreviations used CY cyclophosphamide - i.p. intraperitoneally - s.c. subcutaneously - p.o. orally - i.v. intravenously